They say what goes around comes around, and it’s never been more accurate than in the case of the bottle garden.
These reached the height of their fashion in the 60s and 70s before falling out of popularity. Recently they've enjoyed quite the resurgence.
As indoor gardening enjoys a renaissance, the need for easy-care plants has grown, and there’s little that is easier to maintain than a bottle garden or terrarium.
What is a terrarium and why create one?
A bottle garden is a type of terrarium, as is any glass container holding a growing medium and plants, for example, a Wardian case.
A very large Wardian case housing orchids. Botanist Nathaniel Bagshaw Ward developed the first terrarium in 1842.
Terrariums (or terraria) are usually sealed, but this isn't essential. The benefit of sealing the bottle garden is that they become pretty much zero-maintenance as they negate the need for watering.
The other benefit is that you can grow plants which require stable humidity and temperature levels that are difficult to achieve in the average home.
How to create a bottle garden
It’s very simple to create a bottle garden, Wardian case or other types of terrarium. For carnivorous plants and cacti/succulents, a slightly different setup is required.
What you’ll need:
· A glass container. The size will depend on a) what effect you want in your space and b) what you want to grow.
· Grit or pebbles.
· Activated charcoal (not essential, but removes impurities, keeping the medium fresh).
· A suitable growing medium, such as houseplant compost or peat alternative.
· Houseplants to fill your terrarium. I’ve included a list below to get you started.
An open terrarium is usually better for succulents and cacti due to the watering and low humidity requirements.
What to do:
· Begin by ensuring your container is in good condition and is as clean as possible, remember that the plants will need good light to photosynthesise.
· Wash the grit and place at the bottom of the terrarium. This forms a reservoir which will keep the water separate from the soil, preventing waterlogging.
· Add a thin layer of the activated charcoal.
· Add the growing medium until the bottle is a third full. The level can be lower in a terrarium with straight sides.
· Position your plants inside the terrarium, remaining cautious of their height. Place taller towards the centre/back (depending on the shape of the terrarium and whether you want it able to be viewed from 360°).
· Water sparingly; just enough to moisten the compost. A sealed bottle garden has its own miniature water cycle, so adding too much at this point will flood it.
· Clean the glass both inside and out and seal the container. Place in indirect, bright light. Avoid direct sunlight and dark corners. If the garden is not sealed, then you will still need to keep an eye on watering going forward.
Selaginella is far happier in a bottle garden when grown in the home.
Plants for terrariums
Many of these plants will have caused their owners heartbreak due to their particular demands, but in a bottle garden, they’ll thrive.
You may need to trim your miniature garden occasionally to keep them in check. Flowering plants may need removing once faded and replacing with fresh colour.
The eyelash begonia (B. bowerae is one of the many beautifu foliage begonias suitable for a bottle garden.
First published in May 2019